New Democratic Party of Canada, through its French language acronym NPD, standing for Nouveau Parti Démocratique

New product development, a term used to describe the complete process of bringing a new product or service to market

Narcissistic personality disorder

National Democratic Party of Germany, a nationalist party in Germany; after its German language name, Nationaldemokratische Partei Deutschlands

Nuclear Power Demonstration, an early power-producing nuclear reactor in Canada

NPD Group, a sales and market research company (formerly National Purchase Diary)

New Pudsey railway station, England; National Rail station code NPD.